This invention relates to fluorinated onium sulfonate, especially fluorinated onium sulfonate, antistats and to a process for their preparation.
Typical synthetic organic polymers are not good conductors of electricity, giving rise to a buildup of static charges. These in turn cause the polymers to attract dust or dirt, cling to other surfaces, and cause other difficulties in their processing or application. Phosphonium sulfonates, for example, have been found to be effective antistats when incorporated in such organic polymers, particularly those wherein the sulfonate moiety contains a perfluorinated organic chain. Such phosphonium sulfonates have also been found useful in improving the electrostatic transfer efficiency of toner powders used in electrostatic copying. Most know processes for producing a tetraalkylonium perfluoroalkylsulfonate require one or two ion exchange steps. Though U.S. Pat. No. 5,051,330 discloses reacting M+(R1)(R2)(R3)(R4)Xxe2x88x92 with Li+(R6)SO3xe2x88x92 to produce a fluorinated onium sulfonate M+(R1)(R2)(R3)(R4)(R6SO3xe2x88x92), the patent does not disclose or suggest any reaction conditions. Nor does it disclose or suggest how the reaction is driven to completion. Nor does it disclose or suggest the reaction of a perfluoroalkyl sulfonate salt with a tetraalkyl phosphonium halide. Therefore, there is a need to develop a process for the manufacture of a tetraalkylonium perfluoroalkyl sulfonate in which the process does not include an ion exchange step.
This invention provides a process that can be used for manufacturing a tetraalkylonium perfluoroalkyl sulfonate. The process comprises (1) combining an aqueous solution of a tetraalkylonium halide and an aqueous solution of a metal perfluoroalkyl sulfonate to produce a mixture; (2) allowing the mixture to form an aqueous upper phase and a separate liquid lower phase; (3) separating the lower phase from the upper phase; and (4) drying the lower phase or washed lower phase, preferably under vacuum conditions. The process can comprise, after step (3) and before step (4) washing the lower layer with water to produce a washed lower phase, which can be then dried.